Using 32mm plumbing pipe means that are a large number of bits and bobs that attach to the pipe are available – reducers (as previously mentioned to make mouthpieces), bends of different angles and shapes.
Rather than suggest what you can do I will (as time allows) put a load of photos on this page of different concoctions. If you have any images of what you have made, by all means let me know and I can put the image(s) on this page.
Buying the Right